1. Field
The subject matter disclosed herein relates to data communication. In particular, the subject matter disclosed herein relates to data communication in a data link.
2. Information
Data transmission standards directed to high speed communication over optical transmission media such as 10 and 40 Gigabit Ethernet, or Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) have brought about a need for high speed communication between components or modules in systems employing such standards. For example, IEEE P802.3ae defines a 10 Gigabit Attachment Unit Interface (XAUI) to transmit data between 10 Gigabit Media Independent Interfaces (XGMIIs) through a data link. Also, the Optical Internetworking Forum (OIF) defines System Packet Interfaces (SPIs) at Levels SPI-1 through SPI-5 for different data rates.
Serial links typically transmit encoded symbols on each of a plurality of parallel data lanes coupled between a source and destination. Symbols received from each data lane at the destination are typically decoded to provide bits to be combined with decoded data received from other data lanes. Due to physical characteristics of the data link, the data received from the data lanes may become temporally misaligned or skewed. Accordingly, symbols or decoded data received from the data lanes is typically re-aligned or deskewed prior to combining. Alignment character symbols are typically inserted in to data lanes to enable realignment of the data lanes at a destination as described in IEEE standard 802.3—2000, clause 36.